1. Field of the Invention
This invention relates to a liquid crystal display.
2. Description of the Related Art
In recent years, liquid crystal display devices are being used as a display device that is thin, light weight, and space-saving, and has a less power consumption. In particular, devices with two substrates with liquid crystal interposed in between: one substrate having a plurality of thin film transistor (TFTs) and a plurality of pixel electrodes thereon in a matrix form; and another substrate having color filters (CFs) thereon for enabling color display, are called “active matrix type,” and are very popular nowadays. Here, the glass substrate on which TFTs are disposed is called the “TFT substrate.” And the glass substrate that has color filters is called the “CF substrate.” Typically, the CF substrate has a common electrode formed thereon, and the TFT substrate has a connection electrode (hereinafter also referred to as “transfer electrode”) that is used for connecting the TFT substrate to the common electrode of the CF substrate.
In a conventional active matrix type liquid crystal displays, a transfer electrode on the TFT substrate is connected to the common electrode on the CF substrate via conductive particles. FIG. 10 is a schematic cross-sectional view of such a structure. TFT substrate 1 and CF substrate 2 are coupled to face each other with a set spacing. On the TFT substrate 1, a plurality of TFTs and a plurality of pixel electrodes respectively connected to the TFTs are disposed. In addition, a transfer electrode 9 is formed near the edge of the TFT substrate 1. A polarization plate 5 is affixed on the lower surface of the TFT substrate 1.
Another polarization plate 4 is affixed on the upper surface of the CF substrate 4. On the lower surface of the CF substrate 2, color filters 14, which allow light of specific wavelengths to pass there through, and a black matrix (BM) 15 for light shielding are provided. A common electrode 16, which is formed of a transparent conductive material, such as ITO (Indium Tin Oxide), is disposed on the color filters 14 and the black matrix 15. Liquid crystal 3 fills a space formed between the pixel electrodes of the TFT substrate 1 and the common electrode 16 of the CF substrate 2.
Here, the TFT substrate 1 and the CF substrate 2 are coupled via a sealing member 11. In order to set the cell gap to a prescribed value, spacers, which have a size that corresponds to the desired cell gap, and conductive gap members 8, which are conductive particles having a uniform diameter disposed in the sealing member 11, are provided. The transfer electrode 9 of the TFT substrate 1 and the common electrode 16 of the CF substrate 2 are electrically connected via conductive gap members 8.
In the liquid crystal display device described above, the transfer electrode is formed of a metallic material having a relatively low resistivity, such as Al, Mo. However, as shown in FIG. 10, a portion of the transfer electrode is exposed to the exterior at one edge of the TFT substrate, for example. Because of this, the exposed portion of the transfer electrode can be damaged by degradation and/or corrosion that occur due to moisture in the air and/or as a result of exposure to corrosive atmosphere, causing disconnection and poor reliability.